This invention generally relates to optical system analysis, and in particular embodiments provides methods and systems for evaluating and/or treating an eye of a patient, generally through the use of point spread functions tailored to model the patient's visual perception. Other embodiments make use of volumetric point spread functions spread throughout an imaging distance range. Graphical representations of perceived point spread function and/or volumetric point spread functions can validate a patient's perception, and may be used to develop a specific prescription for the patient or new classes of refractive corrections for a number of patients.
An individual's visual perception can be measured in a variety of different ways, and can be affected by a number of different factors. Visual acuity is among the more common visual perception measurements. Traditionally, measuring visual acuity of the human eye has involved using eye charts. Visual acuity measurements can be affected by objective factors such as the optical characteristics of the cornea and lens, as well as subjective factors such as light absorption and detection in the retina, neural processing in the brain, and the like. While visual acuity measurements can provide a good overall measurement of visual perception capabilities, they provide little guidance regarding the specific defects or weaknesses of the visual system which might be limiting visual perception for a particular patient.
More recently, objective measurements of optical performance of the eye have been made possible. Wavefront measurements using Hartmann-Shack sensors now allow optical aberrations to be measured across the optical system. From these aberration measurements, a variety of objective optical performance characteristics may be calculated. These objective optical aberration measurement and calculated performance characteristics have significantly advanced the art of diagnosing and treating a patient's optical tissues over the last several years. It is now common, for example, for aberration measurements of a patient to be used for developing custom prescriptive refractive corrections for the patient's eye, with these prescriptions often being imposed using laser eye surgery. By combining the new objective aberration measurement techniques with the laser refractive correction capabilities of laser eye surgery, many patients can have both lower order optical errors (such as myopia, hyperopia, and astigmatism) and higher order aberrations partially and/or substantially fully corrected, thereby providing many patient's with visual acuities of greater than 20/20.
As with many such successes, however, still further improvements would be desirable. In particular, the known objective visual performance characteristics now being calculated from aberration data do not capture many of the subtleties of the human vision system. Wavefront measurements and calculated aberration characteristic displays, for example, are often not intuitively understood by the great majority of patients.
In light of the above, it would be generally desirable to provide enhanced systems and methods for diagnosing, analyzing, and treating aberrations of a patient's eye. It would also be beneficial to provide enhanced visual perception effect models and graphical representations which more precisely match the patient's perception. It would be particularly advantageous if these improvements could make use of the objective aberration measurements now available and could both more closely model the patient's perception from their visual system.